Abstract:

BACKGROUND: The bacterial microfloras in chronic venous leg ulcers (CVLU) play an important role in the healing process, but there is still considerable debate as to the importance of individual species or microbial density in relation to healing.
OBJECTIVE: To explore the relationship between the bacterial groups frequently recovered from chronic venous leg ulcers and ulcer healing.
METHODS: Patients with newly diagnosed chronic venous leg ulcers in the First Affiliated Hospital of Chongqing Medical University from 2009.5 to 2010.9 were recruited in this study.Totally 39 patients with 42 chronic venous leg ulcers included in this study were treated with standard regimen of compression therapy. Patients were followed up for 6 months to determine healing rates of ulcers. Twenty-eight ulcers with 100% closure of the wound and did not reoccur within 1 month of wound closure were included in the healing group. Fourteen legs without complete healing served as non-healing group. Tissue samples from ulcer bed were obtained by biopsy prior to treatment, DNA was extracted directly from the tissue sample. A set of universal primer and group or species-specific primers for the bacterial groups frequently recovered from CVLU were synthesized. The bacterial difference between healing and non-healing chronic venous leg ulcers was compared using PCR and real-time fluorescence quantitative PCR.
RESULTS AND CONCLUSION: Bacteria were detected in all ulcers. In the healing and non-healing groups, the most common bacteria were staphylococcus aureus and pseudomonas aeruginosa. Quantitative RCR showed that the total bacterials load in the non-healing chronic venous leg ulcers was significantly higher than those of healing group (P < 0.05), whereas the density of staphylococcus aureus and pseudomonas aeruginosa did not show significant difference (P > 0.05). In this study, no single bacterial species or group frequently recovered from CVLU was shown to be associated with healing outcome. This study suggests that the increase of total bacterial load play important roles in maintaining a chronic inflammation state that ultimately leads to the failure of chronic venous leg ulcers to heal.